"TRPA1 is also present on nerve endings in blood vessels and its activation leads to vasodilatation, which is an important component in inflammation," said study co-author Edward Högestätt. "Thus our findings may help to develop drugs acting on TRPA1 for treatment of pain and inflammation."

Compounds in chili peppers and in mustard plants also trigger the TRPA1 pain receptor. Scientists speculate that all three plants may have developed similar chemical irritants during their evolution.

The findings may shed a little light on the neurochemistry behind good cooking.

"Together with taste and smell, oral sensation of pain play[s] an important role in determining food flavor," Högestätt said. "Thus, targeting TRPA1 with pungent spices like mustard, wasabi, and garlic may contribute to successful cooking."

"It's Chic to Reek"

But you don't need a Ph.D. to appreciate the punch garlic packs in the kitchen.

Gene Sakahara, past president of the garlic festival in Gilroy, California, appears as a celebrity chef at the event's Great Garlic Cook-Off.

In an e-mail interview, Sakahara compared the taste of garlic, chili, and wasabi, which is made with mustard plant. "Raw garlic has a hotter flavor. But as a cooked herb, it becomes sweeter and [a] flavorful adding to any gourmet dish," he said. "Chili, as it simmers, takes on a hotter taste and pleases those who like hot and spicy foods."

"Wasabi, by itself, has the initial nasal rush, then adds to the flavor of the sushi," he said. "Of course, my favorite is still garlic. It's chic to reek."